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Hi all,
Brand new to this site. Appreciate in advance everyones feedback and guidance. I have a 2015 C400 55kmiles. I need front brakes and I'm looking to change myself. Just wondering if there is a way to tell ahead of dismantling everything if I would need to change the rotors as well. Would love to save some time/money and simply change the pads only but looking for guidance..
Thanks all!
In my opinion its best to replace both pads and rotors at the same time. From all my searching around it looks like most MB rotors have a wear limit of around 2mm. Example if the new rotor measures 28mm then if it reaches down to 26mm they say replace it. I also remember reading something where it warns against having the rotors machined, ill try and look for that.
The max and min thickness should be stamped right on the hub part of the rotors when you remove the wheel. If you can feel a lip on the rotor then chances are its worn and should be replaced. Remember if you just replace the pads the old rotor will be on the car along time, dont want it going down below the minimum before the pads wear.
I found a useful sheet from MB showing what exactly should be greased and what should NOT be greased. I have been following it since i replaced the brakes over 5yrs ago and have had no issues with them.
Ill post an example of the brake rotor thickness specs. Im not sure your exact submodel.
Not sure your location. When I replaced my brakes I bought all the parts from FCP Euro specifically for the lifetime warranty. I think its worth it for expensive things like brakes. next time I have to replace them just send all the used parts back and get store credit.
Tim -
Thanks so much for all the info and details! I've watched some videos on the swap out on pads and rotors and what I cant seem to figure out is if I will need a specialized tool to compress the pistons on the caliper. I believe on the C400 I have a 4 piston caliper and I know they have to be compressed at the same time so I think I need a specialized tool but just not sure which one I need to fit my model.
Appreciate any guidance you might have.. Jeff
To push the pistons back I can usually do it by hand without any tools. Leave that old brake pad still installed, grab each side pressing your palms against the pad as your reaching around with your fingers on the caliper. Have the brake fluid reservoir cap open as you do it. if its too hard by hand I have a huge pair of channel locks I can use, same concept leave the old pad on and press the piston/pistons in.
But i've only done single piston calipers. Im not exactly sure how a 4 piston needs to go back, if they have to be pressed in each side at the same time. I'll post what it says for pressing the pistons back and the tool. They have various ones on Amazon, Ill show an example.
Yes if it's four piston calipers the tool TimC300 shows you simply put the old brake pads in the caliper and use them with the tool to push the pistons all in at the same time. Single piston calipers are a piece of cake to push in.
Last edited by RobertR728; Apr 16, 2025 at 07:32 PM.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
This (or one similar) also works well. If you decide to do your rear brakes in the future, you will need to put them into the service position. That can be done with a proper scan tool or through menus in your instrument cluster.
Thanks JettaRed!
One question with regards to your point about placing into service position. Thats only necessary for the rear brakes? Any idea why? Curious to learn...
Thanks again!
~Rx
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